The purpose of this study is to examine whether guanfacine or carvedilol will attenuate the ability of stress to precipitate smoking lapse behavior in treatment seeking and non-treatment seeking daily smokers. Participants seeking treatment for smoking will participate in a smoking cessation attempt after the laboratory sessions. Also looking at gender differences.

3 mg/day, with 3-week lead-in medication period. The starting dose is 0.5 mg/day for days 1-3, followed by 1.5mg/day for days 4-7, followed by 2 mg/day for days 8-12, followed by 2.5 mg/day for days 13-15, followed by 3 mg/day from day 16 to remainder of study. 5-day taper at end of study.

Other Name: Tenex

Placebo Comparator: Placebo

placebo control

Drug: placebo

placebo

Experimental: Carvedilol

Carvedilol 50 mg/day

Drug: Carvedilol

50 mg/day titrated to stead state. The starting dose is 12.5 mg/day for day 1, followed by 25 mg/day for days 2-3, followed by 50 mg from days 4 to the end of the study.

Other Name: Coreg

Eligibility

Ages Eligible for Study:

18 Years to 60 Years

Genders Eligible for Study:

Both

Accepts Healthy Volunteers:

No

Criteria

Inclusion Criteria:

ages 18-60

able to read and write in English

smokers

Exclusion Criteria:

any significant current medical conditions that would contraindicate smoking

current DSM-IV abuse or dependence of other substances, other than nicotine (or caffeine) dependence

positive test result at intake appointments on urine drug screens conducted for opiates, cocaine, or benzodiazepines

women who are pregnant or nursing

suicidal, homicidal or evidence of severe mental illness

participants prescribed any psychotropic drug in the 30 days prior to study enrollment

blood donation within the past 6 weeks

participants who have engaged in a quit attempt in the past 3 months

specific exclusions for administration of guanfacine/carvedilol not already specified include: Hypotensive individuals with sitting blood pressure below 90/50 mmHG; EKG evidence at baseline screening of any clinically significant conduction abnormalities, including a Bazlett's QTc >450 msec for men and QTc>470 msec for women; known intolerance for guanfacine

Contacts and Locations

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study.
To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below.
For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00773357